Insomnia is the most common sleep disorder. Insomnia is considered a hyper-arousal disorder in which both cognitive and physiological domains are over-activated. Research has shown that insomnia is associated with elevated autonomic nervous system activation, particularly at sleep onset, which can adversely impact a person's health and wellbeing in a number of ways. Sleep onset in insomniacs is characterized by high levels of cognitive activity, worry, rumination and intrusive thoughts that, together with the autonomic hyperactivation, impede the onset of sleep. Predisposing factors that can increase a person's vulnerability to insomnia include age, gender, coping strategy, personality traits, and genetic factors. Insomnia can be triggered by acute stressful events, such as illness or trauma; it can be a chronic disorder without specific cause, or can be a symptom of other disorders. Perpetuating factors, such as the use of caffeine or alcohol, excessive worry, and irregular wake/sleep schedules, may contribute to the development and persistence of insomnia.
Cognitive-Behavioral Therapy (CBT) and pharmacotherapy are two main lines of treatment that are currently available for insomnia. However, many insomnia sufferers do not wish to use pharmacotherapy and there is limited availability of CBT.